While training is the primary factor that contributes to a stellar race day performance, Pearl Izumi's P. R. O In R Cool Tri Shorts are designed to work with you by reducing drag, regulating your core temperature, and supporting the muscles of the leg. The shorts were sewn from Pearl's proprietary In R Cool fabric. Unlike common dark textiles, which absorb heat, these fabrics have a UPF rating of 50 and reflect the sun's radiant energy. This reduces the fabric's surface temperature in order to avoid overheating during the ride and run stages on hot, sunny days. Also keeping you cool is Pearl Izumi's proprietary P. R. O. Aero fabric, a blend of nylon, elastane, and polyester. The resulting engineered knit produces an outer surface that's optimized to smooth turbulent air and reduce drag, and as stated above, it also provides core comfort. It's textured for breathability and to accelerate moisture transfer away from the skin. And by keeping your skin cool and dry, irritation on the bike and run is minimized.Providing a lightly compressive fit that maximizes muscle efficiency, the P. R. O In R Cool's multi panel design ensures that the shorts provide the greatest degree of mobility by working with the Aero fabrics natural stretch in order to eliminate binding. It has a stretch draw cord to securely hold the shorts in place, and an easy access envelope pocket that gives you a place to stash small items.For further comfort, Izumi also included its TRI quick dry chamois. This insert is constructed with variable density padding that's contoured for an anatomically correct fit. Its minimal design makes it nearly unnoticeable during the swim and run portions of your race. The Pearl Izumi Elite In R Cool Tri Shorts are available in four sizes from Small to X Large and in the color Black.